N = int(input())
S = input()
A = list(map(int, input().split()))

res = 0
maxs, mins = 0, 0
for i in range(N):
    v = A[i] if S[i] == 'R' else -A[i]
    maxs = max(maxs + v, v)
    mins = min(mins + v, v)
    res = max(res, abs(maxs), abs(mins))
        
print(res)